docs: def delete_instance(self, nova, instance):
          """Delete the specified instance."""
  
          # /!\ DEPRECATION WARNING
          self.log.warn('/!\\ DEPRECATION WARNING:  use '
                        'delete_resource instead of delete_instance.')
          self.log.debug('Deleting instance ({})...'.format(instance))
          return self.delete_resource(nova.servers, instance,
                                      msg='nova instance')